Starting left guard Jason Pinkston remains hospitalized with blood clots in his lungs, a life-threatening condition he's grateful was detected early. After the Browns revealed Pinkston's condition after practice on Friday, he confirmed his illness on Twitter while being treated at the Cleveland Clinic.

"The news is true I've been hospitalized with blood clots in my lungs very thankful our medical staff did a great job of taking action," Pinkston wrote on his account. "And catching it at a early stage it's obviously clear I won't be playing for sometime but more importantly I'm thankful to be alive."

It's believed the blood clot contributed to him becoming ill in last week's win over Cincinnati. Pinkston will not play Sunday against Indianapolis and the Browns do not know when the second-year guard will be released from the hospital or cleared to return.

Browns coach Pat Shurmur disclosed Pinkston's medical issue after the team's last workout, concluding a week in which Jimmy Haslam was approved by the NFL as Cleveland's new owner, former Eagles president Joe Banner was introduced as the team's CEO and Republican vice presidential nominee Paul Ryan and former Secretary of State Condoleezza Rice visited practice.

Shurmur did not provide many specifics about Pinkston, a second-year guard from Pittsburgh. Several of his teammates visited Pinkston in the hospital on Thursday night.

"We're definitely concerned and our thoughts are with him," Pro Bowl left tackle Joe Thomas said. "Obviously, it's a little bit scary, but I guess we're definitely going to keep in touch with him and hopefully things will be all right."

Shurmur would not say where Pinkston's blood clot is located. He does not know how long the 25-year-old will be sidelined or if he will need to have surgery.

"We'll just have to see," Shurmur said. "What I'll tell you is, he's being treated for a blood clot. He's going to miss this week. As we go through next week, we'll determine if he's going to miss an extended period of time."

Pinkston started last week's win over Cincinnati but wasn't feeling well and was replaced by John Greco, who played the entire second half. Pinkston practiced as recently as Wednesday but missed Thursday's workout and was listed on the team's injury report as being out with an "illness." Shurmur did not know if Pinkston feeling ill last Sunday was related to the blood clot.

Greco, a five-year veteran, will start this Sunday against the Colts. Greco played in 15 games for Cleveland last season after the Browns acquired him in a trade from St. Louis.

Greco was one of the players who visited Pinkston in the hospital.

"We saw him last night," Greco said. "We went to say hi to him, just to keep his spirits up a little bit and tell him we were with him."

Pinkston started all 16 games in 2011 as a rookie. He played tackle in college, but was switched to left guard last season after Eric Steinbach sustained a season-ending back injury. The 6-foot-4, 305-pound Pinkston worked hard in the offseason on his conditioning and improve his techniques as a run blocker and pass protector.

Thomas said Pinkston had made big strides.

"He's been playing really well and it definitely hurts not having him this week," Thomas said. "I think John did a really nice job last week and we're really confident about him stepping in and doing a good job."

Greco got the majority of practice time with the first-team offense this week, and Thomas said that should help the line's overall rhythm as they face a Colts team that gave up 252 rushing yards last week to the New York Jets.

"I think it's going to help both of us," Thomas said. "When you're the backup, you don't get a whole lot of reps, maybe five or six every day, so being able to go from that to 40 or so is going to be really helpful for everybody. I think just the comfort level is going to be improved."

Browns wide receiver Greg Little returned to practice after being sent home Thursday with flu-like symptoms.

NOTES: Starting LB Scott Fujita was on the practice field as a spectator. Fujita may be out for the season with a neck injury that could also end his career. Fujita was not available for comment during the period the locker room was open for media members. With Fujita out, rookie James-Michael Johnson will get his second straight start. .... CB Dimitri Patterson remains sidelined with an ankle injury. ... Rookie RB Trent Richardson practiced with a protective jacket over his rib cartilage injury. Richardson wants to play, but the Browns may limit their young star.